Closed electric machine



Jan. 31, 1928.

H RICHTER CLOSED ELECTRIC MACHINE Filed Nov. v, ,19255 Patented Jan. 31, 1928.

UNITED STATES PATENT OFFICE.

CLOSED ELECTRIC MACHINE.

Application filed November 7, 1925, Serial No. 67,653, and in Germany November 7, 1924.

My invention relates to a closed electric machine which works immersed in a liquid and more particularly to a mine pump motor.

For raising naphtha, brine, water or the like from bore holes, electrically driven mine pumps are employed which are inserted into the bore holes, together with the delivery pipe, and immersed in the liquid. The drivis located below the pump. is cooled by the liquid sucked up. The liquid should, however, not penetrate between the active parts of the motor. For this purpose, the motor is encased, and the f shaft of the motor is passed into the pump chamber through a stutling box. It has, however, been found that the packing of the stuffing box exerts a strong braking action upon thc shaft and thus upon the motor, and that the packing' becomes excessively heated if it is suiiiciently tight to fulfill its purpose. v

In order to eliminate this waste of energy, a perfectly acting shaft packing is abanoned, according to my invention, and the penetration ofa small quantity of the liquid into the machine is permitted. To neutralize this as far as possible, provisions are, however, made which render the penetration of the liquid into the bearings and windings impossible, or at least difficult, as well as the collection of the liquid in the immediate vicinity of the active parts of the motor. The liquid which has penetrated through the packing is collected ina receptacle which is drained by a bilge pump coupled with the motor, in a known manner.

To' prevent a drowning of the machine during intervals in the operation of the mine pump and while the. bilge pump is stopped, sealed in a. known the passage of the shaft is manner by a valve which closes automatically when the machine is stopped, but which is raised od its scat when the machine is started again, in order to avoid friction losses.

The object of my invention is to provide a closed electrical machine, adapted to operate while immersed in a liquid, with a particularly simple, but suitably designed, device for protecting the active parts against .the penetrating liquid.

During intervals in the service, the pas.- sage of the shaft is closed by a valve. A e- `may equally well be cording to my invention, the valve disc surrounding the shaft is tightly and firmly and both the valve displaceable in an axial direction. The shaft thus forms the valve rod and ensures a good guidance of the valve disc. The valve seat consists of a member tightly fitting the casing and surrounding the shaft ,annularly This valve is distinguished from known designs by extreme simplicity and reliability in operation. When the pump is started, the valve disc is raised off its seat by a centrifugal governor in a known manner. This governor, according to my invention, is located in the interior of the casing and is in operative engagement with the shaft of the machine. As soon as a 'predetermined speed is attained, the governor displaces the Shaft in relation to its bearings and thus lifts the valve disc off its seat.

Another object of my invention is the cleaning of the seat of the valve. According to my invention, the valve is placed in the path of the penetrating liquid between the stuffing box of the shaft passage and the collecting receptacle for the liquid which has already penetrated the stuffing box.

is arrangement has/ theadvantage that t-he stufiing box acts as a filter and prevents impurities suspended in the liquid from entering the valve.

On account of the small diameter of the bore holes, the machine is of elongated narrow design. The shaft is vertical while the machine is in service. If the shaft extends out at the top of the motor, the collecting receptacle for the penetrated liquid is preferably located below the machine and is connected with the shaft passage by a channel or duct traversing the sheet-iron stampings of the stator member.

The vertical shaft permits the utilization of the weight of the rotor for closing the valve. According to my invention, the valve disc is pressed down upon its seat by the weight of the rotor. The centrfugal governor then raises the rotor at a predetermined speed. F or lifting the rotor, the magnetic pull which the stator exerts upon the rotor utilized.

An embodiment of my invention is illustrated in the drawing affixed hereto, wherein Fig. l is a vertical sectional view of the upper part-of a sinking pump or mine pump which permit an axial displacement of .the

I 33 collects,

` ported upon the thrust shaft to a small extent. During operation, the shaft 6 is supported by the noses 10., 11 of the centrifugal weights 12, 13 through the agency of the sleeve or bushing 9. The centrifugal weights are rotatably mounted at 14 and 15 upon the ring -16 which is supball-bearing 17. In the inoperative position, the iy-we1ghts rest upon the sleeve 9. The journal bearing 7 1s protected against the entry of liquid or the escape of the bearing lubricant by the packings 18, 19; the journal bearing 8 by the packings 20, 21; and the thrust-bearing 17 furthermore also by the packing 22. The bearing 7 and the kpackings -18 and 19 are supported by the parts 23, 24, the bearings 8, 17 and the packings 20, 21, 22 by the parts 25 and 26. The parts 23 to 26 are mounted upon the pipe sections 27 and 28. which are joined to the pipe 1 by the sleeves 29 and 30.

The whole larrangement is closed at the top by the end member 31 and at the bottom by the'v receptacle or container 32. The top member 31 is provided witha stuffing-box 33 through which the motor shaft 6 extends. The shaft is carried upward to the pump of which only the coupling 34 is indicated in the drawing. Below the stuffing-box 33 a valve disc 35 is mounted on the shaft 6 by means of akey and an annular nut 37. The liquid penetrating through the stufling-box during intervals in the service, in the annular chamber 38, and iows, during the operation of the pump, through the openedvalve 35 and the channel 39, 40, into enlarged top end of a tube 41 which extends'through the stator winding 3 and the stator'stampings 2. From thetube 41, the liquid iows through the chamber 42, 43 and the opening 44 into the container 32. From the lowest placeA 45 of the container 32, the r'iuid is discharged, through a vertical tube 46, by means of an auxiliary pump 47 which forces the fluid through a valve 48. The tube 46 and the auxiliary pump 47 are attached to the motor shaft 6. The valve disc 35 rests ona seat 36 on. the part 24 during the intervals in the service.

The device operates in the following mannerz'during the carrying the valve disc 35, is raised by the centrifugal weights 12 and 13, in order to prevent rubbing contact of the disc with its container 32 in the manner normal service, the shaft 6,v

seat. The liquid which has penetrated through the stuffing-box 33 passes into the described, and is continually drained out of it by means of the auxiliary pump been switched off, the centrifugal weights 12` 13 approach each other under the action of the weight of the rotor and the shaft and allow the shaft to drop until the valve disc 35 restsupon its-seat at 36. rotor and the shaft exert a pressure upon the valve disc. During the service intervals, the liquid penetrating through the top stuflingbox 33 is caught in the annular chamber 38 above the valve disc 35. The valve 435, 36 prevents the liquid from penetrating into the interior of the motor, through the packings 18 and 19. When the motor is started again, the centrifugal Weights 12, 13 raise the shaft 6 with the valve 35, and the liquid which has collected in the chamber 38 Hows through the valve into the container 32 in the manner specified above. From there it is discharged from the motor by theauxiliary pump 47. The normal service state is thereby resumed again.

The valve 35, 36 may be located above the stuiing-box 33, but the design illustrated is preferable because the stuffing-box 33 prevents the entry of sludge and sand into the seat of the valve, 1n the manner of a filter.

Various modifications may be made in the device, embodying my invention Without departing from-the spirit and scope thereof and I desire that all such modifications shall be included in the appended claims ,which are to be limited only by the prior art.

I claim as my invention l. In a closed electrical machine adapted to operate immersed in a liquid and comprising a collecting vessel for the liquid penetrating through the stufiing box of the shaft and a valve adapted to seal said stuffing box when the shaft is inoperative and to be raised off its seat when said shaft is operative, a valve disc tightly mounted] upon said shaftand adapted to be moved axially together with said shaft and a centrifugal governor located within the machine casing and adapted to displace said shaft in'relation to its bearings and to control said valve.

2. In a closed electrical'machine adapted to operate immersed in a liquid and comprising a collecting vessel for the liquid penetrating through the stuffing box of the shaft and a valve adapted to seal said stuffing box when the shaft is inoperative and to be raised'off its seat when said shaft is operative, a valve disc tightly mounted upon said shaft and adapted to be moved axially together with lsaid shaft and a centrifugal governor located within the machine casing and adapted to displace said shaft in relation to its bearings and to control said valve, said valve being located be- 47. After the motor has The weight of the lll) lil)

the vital parts of the motor,

mamon tween said stalling box of the shaft and said vcollecting vessel for the liquid which has penetrated into said machine casing.

3. In a closed electrical machine adapted to operate in'imersed in a liquid with a vertical shaft carried through at the top and comprising a collecting vessel for the liquid penetrating through the stuffing box of the shaftand adapted to be drained by a bilge pump and a valve adapted to seal said stalling box when the shaft is inoperative and to be raised ott' its seat when said shaft is operative, a valve disc tightly mounted upon said shaft and adapted to be moved axially together With said shaft and a centrifugal Weight located Within the machine casing and adapted to displace said shaft in relation to its bearings andl to control said valve, said valve being located between said stufling box of the shaft and said collect-ing vessel for the liquid which has penetrated into said machine casing, said collecting ves- `sel being located below said machine, and sheet-iron stampings, in the machine containing a channel adapted to put said collecting vessel in communication With said stalling box.

4. In a closed electrical machine adapted to operate immersed in a liquid and comprising a collecting vessel for the liquid penetrating through the stuiiing box of the shaft and a valve adapted to seal said stuiiing box when the shaft is inoperative and to be raised ott its seat when said shaft is operative, a valve disc tightly mounted upon said shaft and adapted to be pressed upon its seat by the Weight of the rotor of said machine, and a centrifugal governor located within the machine casing and adapted to raise said rotor at a predetermined speed of said shaft, said valve being located between said stuiling box of the shaft and said col-v lecting vessel for the liquid which has penetrated into said machine casing, said collecting vessel being located below said machine, and sheet-iron stampings in the machine containing a channel adapted to put said collecting vessel in communication with said stuffing box.

5. A submersible motor having an enclosing casing, ya shaft extending out of said casing, an imperfect packing for the'shaft, a reservoir at the bottom of the casing for collecting fluid which enters the casing and for keeping said Huid out of contact With the vital parts of the motor, and means for expelling the fluid from said reservoir.

6. A submersible motor having an enclosing casing, a shaft extending out of said casing, an imperfect packing for the shaft, a reservoir at the bottom of the casing for collecting fluid which enters the casing and for keeping said fluid out of contact with a substantially fluid-tight, releasable valve member surrounding said shaft and operable to eliminato substantially all leakage, means for, at times, releasing said valve member whereby the frictional drag on said motor may be materially reduced, and means for expelling the iuid from said reservoir.

7. A submersible motor having an enclosing casing, a shaft extending out of said casing casing, a. shaft extending out of said lcasing, an imperfect packing for the shaft,

a reservoir at the bottom of the easing for collecting fluid which enters the casing and for keeping said Huid out of contact with the vital parts of the motor, a substantially fluid-tight, releasable valve member surrounding said shaft and operable to eliminate substantially all leakage, automatic means for causing said valve member to be closed When the motor is at rest and for causing said valve member to be released when the motor is operated, whereby the frictional drag on the motor may be materially reduced, and means for expelling the fluid from said reservoir.

9. A submersible motor having an enclosing casing, a shaft extending out of said casing, an imperfect packing for the shaft, a reservoir at the bottom of the casing for collecting fluid which enters the casing and for keeping said fluid out of contact With the vital parts of the motor, a substantially fluid-tight, releasable valve member surrounding said shaft and operable to eliminate substantially all leakage, automatic means for causing said valve member to be closed When the motor is at rest and for causing said valve member to be released When the motor is operated, whereby the frictional drag on the motor may be materially reduced, and means coupled to said shaft for expelling the iluid from said rcs-` ervoir.

10. A submersible motor having an enclosing casing, a shaft extending out of said casing, variable leakage-preventing means surrounding said shaft, means responsive to the operation of the motor for varying said leakage-preventing means from a. substantially fluid-tight, heavv frif'tion jointto a. relatively leaky, light-friction joint, a reservoir at the bottom of the casing for collecting Huid willich enters the casing and for keeping said -uicl out of 'Contact with the vital parts of the motor, and means for expelling the Huid from said reservoir. l

ll. A submersible motor having an enclosing easing, a shaft extending out of said easing, variable leakage-peventing means surrounding said shaft, means responsive to the operation of l* leakage-preventing means from the motor for va-Iyn said a su stantially fluid-tight, heVy-'friction joint to a relatively leaky, light-friction lioint, a reser- Voir at the bottom of the casing for colleet- 

